Embodiment
Describe Electrostriction composite material of the technical program and preparation method thereof in detail below with reference to accompanying drawing.
See also Fig. 2, the technical program embodiment provides a kind of Electrostriction composite material 20, it comprises a flexible macromolecule substrate 22, is dispersed in a plurality of carbon nano-tube 24 in the described flexible macromolecule substrate, and is dispersed in a plurality of ceramic particles 26 in the described flexible macromolecule substrate 22.Described carbon nano-tube 24 evenly distributes in described silicone rubber substrate, and carbon nano-tube 24 is overlapped on mutually and forms a large amount of conductive networks in the flexible macromolecule substrate 22.Flexible macromolecule substrate 20 can be selected from a kind of and combination in any in silicone elastomer, polyurethane, epoxy resin, the polymethyl methacrylate.Described ceramic particle 26 can be selected from a kind of and combination in any in aluminium nitride, aluminium oxide, the boron nitride.
The mass percentage content of described flexible macromolecule substrate 22 in described Electrostriction composite material 20 is more than or equal to 90%; Carbon nano-tube and the ceramic particle mass percentage content in described Electrostriction composite material 20 is smaller or equal to 10%.For guaranteeing that carbon nano-tube 24 can form a plurality of conductive networks in described Electrostriction composite material 20, so the mass ratio of carbon nano-tube 24 and ceramic particle 26 was more than or equal to 1: 1.Preferably, the weight percent content of described ceramic particle is 1%~5% of a whole Electrostriction composite material 20.Carbon nano-tube 24 can be a kind of and combination in any in Single Walled Carbon Nanotube, double-walled carbon nano-tube and the multi-walled carbon nano-tubes, the diameter of Single Walled Carbon Nanotube is 0.5 nanometer~50 nanometers, the diameter of double-walled carbon nano-tube is 1.0 nanometers~50 nanometers, and the diameter of multi-walled carbon nano-tubes is 1.5 nanometers~50 nanometers.
In the present embodiment, described flexible macromolecule base material 10 is a silicon rubber, and carbon nano-tube is a multi-walled carbon nano-tubes, and the length of described carbon nano-tube is 1~10 micron.Described ceramic particle 26 is the aluminium nitride ceramics particle, and the diameter of ceramic particle is 1~100 nanometer.The weight percent content of ceramic particle 26 is 4% of a whole electrostriction material 20, and the mass percentage content of carbon nano-tube 24 is 5% of a whole electrostriction material 20.
Acting as of described ceramic particle 26: one, because ceramic particle 26 such as described aluminium nitride has high thermal conductivity and characteristic such as high temperature resistant, thereby can improve the heat transfer efficiency of described Electrostriction composite material 20, and accelerate the respective rate of described Electrostriction composite material.Its two, ceramic particles such as aluminium nitride 26 have good electric properties such as high resistivity, low-k and dielectric loss, so, mix above-mentioned ceramic particle 26 after, can mediate to the conductivity of described Electrostriction composite material 20.Its three because ceramic particle 26 such as aluminium nitride has advantages such as good mechanical property and high elastic modulus, so, mix above-mentioned ceramic particle 26 after, can improve the modulus of elasticity of described Electrostriction composite material 20, the bigger stress of acquisition under same strain.
When two electrodes are arranged at the relative two ends of described Electrostriction composite material 20, voltage can be put on the described Electrostriction composite material 20 by electrode, at this moment, electric current can transmit by above-mentioned conductive network.Because the thermal conductivity of carbon nano-tube 24 and ceramic particle 26 is very high, thereby make the temperature of described Electrostriction composite material 20 raise fast, and then, make the silicon rubber between the described carbon nano-tube 24 be in molten condition, and the electric current of described Electrostriction composite material 20 increases along with the rising of its temperature, has promptly formed the process of a positive feedback.Because heat spreads to whole Electrostriction composite material 20 apace from the microcosmic part of described Electrostriction composite material 20, like this, owing to thermal expansion, can cause the stretching, extension phenomenon of described Electrostriction composite material 20.Because it is comparatively even that carbon nano-tube 24 in the present embodiment and ceramic particle 26 distribute in Electrostriction composite material 20, therefore the response speed of described Electrostriction composite material 20 comparatively fast and have a bigger expansion and contraction.Particularly, in the present embodiment, the expansion and contraction of described Electrostriction composite material 20 is 1%~8%.
Be appreciated that, when described Electrostriction composite material 20 is prepared into the sample with definite shape, when on described sample, applying certain voltage, because constantly accumulation on the direction that the electric current of electric charge in described Electrostriction composite material 20 extends, produce a tangible deformation thereby make described Electrostriction composite material 20 prolong on the direction that described electric current extends.And the deformation of the above is not obvious aspect vertical with described electric current bearing of trend, thereby when described Electrostriction composite material 20 shrinks, can see a linear contraction as.Thereby when needing the Electrostriction composite material 20 of system one linear contraction, the Electrostriction composite material 20 that can directly use present embodiment to provide need not other somewhat complex design and just can realize linear contraction and bending, has reduced the difficulty and the cost of manufacture of manufacture craft.
The described Electrostriction composite material 20 of present embodiment is carried out expansion performance to be measured.By lead power supply (not indicating) voltage is put on the two ends of described Electrostriction composite material 20.
When not switching on, the original length L1 that records described cuboid Electrostriction composite material 20 is 4 centimetres; The voltage that applies one 40 volts is after 2 minutes, and the length L 2 that records described cuboid Electrostriction composite material 20 is 4.2 centimetres.By calculating as can be known, after energising, the length variations Δ L of described cuboid Electrostriction composite material 20 is 0.2 centimetre.So the expansion and contraction of described Electrostriction composite material 20 is the ratio of the original length L1 of the length variations Δ L of described Electrostriction composite material 20 and described Electrostriction composite material before and after the energising, promptly 5%.
Further, also a silicon rubber thin layer can be set in the upper and lower surface of the described Electrostriction composite material 20 of present embodiment respectively, thereby form a sandwich structure, be about to the described Electrostriction composite material 20 of present embodiment and be clipped between two silicon rubber thin layers.Wherein, the thickness of described silicon rubber thin layer is 1~10% of described Electrostriction composite material 20.Because the silicon rubber thin layer is identical with composition of the polymer-based ends 22 in the described Electrostriction composite material 20, so can form good combination on the contact-making surface of silicon rubber thin layer and Electrostriction composite material 20.When forming the Electrostriction composite material of same thickness, the Electrostriction composite material of the described sandwich structure of present embodiment is keeping electrostrictive properties preferably, has saved the consumption of carbon nano-tube and ceramic particle, has saved cost.In addition, because described silicon rubber thin layer has good insulation, so can under the Electrostriction composite material situation of needs insulation, use.Be appreciated that the described Electrostriction composite material 20 of present embodiment, also can be according to above-mentioned principle, be arranged to an Electrostriction composite material with sandwich construction, and the set-up mode of each layer and thickness can be adjusted according to actual needs.
See also Fig. 3, the preparation method of the described Electrostriction composite material 20 of present embodiment may further comprise the steps:
Step 1: first component (A component) of mixing carbon nano-tube 24, ceramic particle 26 and silicon rubber forms a mixture, and with the above-mentioned mixture of a volatile dissolution with solvents, thereby forms a solution that contains carbon nano-tube 24 and ceramic particle 26.
In the present embodiment, at first the A component of silicon rubber is mixed with carbon nano-tube 22 and ceramic particle 24, afterwards, add an amount of ethyl acetate, make silicon rubber A component dissolve fully, and form the solution of a carbon nano-tube that contains 24 and ceramic particle 26.Described silicon rubber is to be that 100: 6 hybrid reactions generate by GF-T2A elasticity electron pouring sealant A, B two components by the mass ratio of A: B.In the present embodiment, the mass ratio of silicon rubber 22 in Electrostriction composite material 20 is 91%, and the mass ratio of carbon nano-tube in Electrostriction composite material 20 is 5%, and the mass ratio of ceramic particle in Electrostriction composite material 20 is 4%.
Step 2: the above-mentioned carbon nano-tube 24 and the solution of ceramic particle 26 are handled in ultrasonication, and the above-mentioned solution that contains carbon nano-tube 24 and ceramic particle 26 is handled in ultrasonic cleaning.
Particularly, with the solution of above-mentioned carbon nano-tube 24 of ultrasonic cell disruption instrument sonicated and ceramic particle 26 10 minutes; Afterwards, seal with the solution of preservative film above-mentioned carbon nano-tube 24 and ceramic particle 26, and the solution of carbon nano-tube after will sealing 24 and ceramic particle 26 put into the supersonic wave cleaning machine sonicated 3 hours, thereby made that above-mentioned carbon nano-tube 24 and ceramic particle 26 can be disperseed in above-mentioned solution preferably.Wherein, ultrasonic disruption is handled and can be made to a certain degree the fragmentation of being subjected to of carbon nano-tube 24 and ceramic particle 26, thereby reduces size.Ultrasonic cleaning is handled and can further carbon nano-tube 24 and ceramic particle 26 be distributed in the solution.
Step 3: heat the solution after the above-mentioned sonicated, vapor away the solvent in the solution, form the homodisperse mixture of first component of a carbon nano-tube 24, ceramic particle 26 and silicon rubber.
Particularly, when above-mentioned solution after sonicated is cooled to room temperature, the baking oven of above-mentioned solution being put into one 80 degrees centigrade of constant temperature heats, the ethyl acetate that always is heated in the solution volatilizees fully, forms the homodisperse mixture of first component of a carbon nano-tube 24, ceramic particle 26 and silicon rubber.
Step 4: second component (B component) of silicon rubber is joined above-mentioned in the mixture that heat treated is crossed, mix reaction after, form a compound, and with the surface of this composite coated to one supporter.
Particularly, cool off above-mentioned mixture after heat treated to room temperature, the B component of silicon rubber is joined in the above-mentioned solution, and stir, thereby make silicon rubber B component and silicon rubber A component mix, so that fully react with glass bar.Afterwards, the compound that forms after the above-mentioned reaction is coated to the surface of a supporter with a glass bar, the supporter that light shaking is above-mentioned, thus make described mixture be uniformly distributed in the surface of described supporter.Wherein, described supporter can be silicon chip, glass substrate etc., only need have certain supporting role and get final product, and can select accordingly according to actual needs.
Step 5: the described supporter that is coated with compound is handled in deaeration, forms described Electrostriction composite material 20 after removing supporter.
Particularly, the supporter that is coated with described compound is positioned in the vacuum plant vacuumizes, thereby remove bubble in the described compound.In order to make the prepared Electrostriction composite material of present embodiment have smooth surface, present embodiment adopts a miillpore filter with smooth surface that above-mentioned Electrostriction composite material is pushed, and compound can be coated on equably and entirely the surface of described supporter by extruding.After leaving standstill 12~18 hours, cut with the edge of a blade above-mentioned miillpore filter, thereby the continuous edge of guaranteeing the Electrostriction composite material that finally obtains does not have breakage and non-notch, afterwards, whole Electrostriction composite material is uncovered from the surface of supporter lentamente.
In addition, present embodiment can be further forms a silicon rubber thin layer respectively in the upper and lower surface of described Electrostriction composite material 20, thereby forms a sandwich structure.The preparation method of described sandwich structure is: first component of silicon rubber is dissolved in the volatile solvent, forms a solution; Second component of silicon rubber is dissolved in the described solution, forms a silicon rubber pre-polymer solution; Described Electrostriction composite material 20 is immersed in the described silicon rubber pre-polymer solution, leaves standstill and solidify described silicon rubber pre-polymer solution, can form described silicon rubber thin layer in the upper and lower surface of Electrostriction composite material 20.Because the silicon rubber thin layer is identical with silicone rubber substrate 22 materials in the Electrostriction composite material 20, thereby, above-mentioned Electrostriction composite material 20 directly can be put in the silicon rubber pre-polymer solution and to be formed described sandwich structure, so method is simple, be easy to application.
Described Electrostriction composite material 20 of the technical program embodiment and preparation method thereof has the following advantages: one, owing to dispersed carbon nano tube 24 also comprise great amount of evenly-distributed ceramic particle 26 except that comprising in the described Electrostriction composite material 20.Described ceramic particle 26 has high thermal and high-temperature stability, thereby can improve the heat transfer efficiency of described Electrostriction composite material 20, accelerates the speed of response.Its two because the good mechanical property of ceramic particle 26 and the advantage of high elastic modulus, so the introducing of ceramic particle can improve the modulus of elasticity of described Electrostriction composite material 20, the bigger stress of acquisition under same strain.They are three years old, because ceramic particle 26 has electric properties such as high resistivity, low-k and low-dielectric loss, thereby in described Electrostriction composite material 20, mix a certain amount of ceramic particle, the electric conductivity of the described Electrostriction composite material 20 of scalable, only need apply less voltage can obtain desirable deformation, thereby has reduced the working voltage of described Electrostriction composite material 20.Its four, in forming the process of described Electrostriction composite material 20, thereby make that by adopting ultrasonication to handle described carbon nano-tube and ceramic particle are well disperseed in described Electrostriction composite material.Its five, form a silicon rubber thin layer respectively in the upper and lower surface of described Electrostriction composite material 20, thereby form a sandwich structure.Because the silicon rubber thin layer is identical with composition of the polymer-based ends 22 in the described Electrostriction composite material 20, so can form good combination on the contact-making surface of silicon rubber thin layer and Electrostriction composite material 20.When forming the Electrostriction composite material of same thickness, the Electrostriction composite material of described sandwich structure is keeping electrostrictive properties preferably, has saved the consumption of carbon nano-tube and ceramic particle, has saved cost.In addition, because described silicon rubber thin layer has good insulation, so can under the Electrostriction composite material situation of needs insulation, use.
In addition, those skilled in the art can also do other variation in spirit of the present invention, and certainly, the variation that these are done according to spirit of the present invention all should be included within the present invention's scope required for protection.